Dispenser for multi-texture floss

ABSTRACT

A dental floss dispensing unit includes a housing, a supply spool, and a metering element. The supply spool is coupled to the housing and has a length of floss wound thereabout. The length of floss has a free end extending from the housing and a plurality of alternating and distinct first and second floss segments. The metering element engages the length of floss and provides resistance to removal of the length of floss from the housing. A magnitude of the resistance changes as each floss segment moves into engagement with the metering element, thereby providing a tactilely detectable indication to the user that one of the first or second segments is emerging from the housing. The dispensing unit is configured to allow the supply spool to be manually rotated without manipulation (e.g., disassembly) of the housing for rewinding floss onto the spool.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/975,151, filed Dec. 21, 2010 and published as United StatesPatent Publication No. 2011/0088717 on Apr. 21, 2011, which in turn is acontinuation-in-part of U.S. patent application Ser. No. 12/355,497,filed Jan. 16, 2009 and published as United States Patent ApplicationPublication No. 2009/0194134 on Aug. 6, 2009, which claims the benefitof and priority to U.S. Provisional Patent Application No. 61/024,955filed Jan. 31, 2008. The entire contents of each of these applicationsand publications are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to dental floss, and morespecifically to dental floss comprising segments having differenttextures.

Advancements in materials and manufacturing techniques have resulted ina wide range of options when it comes to dental floss. For example,until fairly recently, dental floss options consisted primarily of waxedor unwaxed floss available in various flavors. Currently however, a widevariety of flosses are available, with each variety having its ownbenefits and limitations. Examples of different materials from whichdental floss is currently made include nylon, Polytetrafluoroethylene(PTFE) or “Teflon®,” ultra-high molecular weight polyethylene (UHMWPE),and polyester, among others.

Another dental floss option relates to the texture of the floss. Someflosses, such as those formed of PTFE, are designed to be relativelythin and smooth, which allows them to more easily pass through the spacebetween adjacent teeth. Other flosses are designed to be relativelythick, textured, or coarse to remove plaque and other debris moreeffectively from the larger spaces between adjacent teeth. While manypeople appreciate the ease of use associated with a relatively thin andsmooth floss, many dentists recommend the thick and coarse floss formore effective cleaning.

SUMMARY

In some embodiments, the invention provides a dental treatment device inthe form of a thread or floss, the thread including a plurality of firstsegments and a plurality of second segments. Each first segment extendsa first length and includes a first texture and a first cross-sectionaldimension. Each second segment extends between adjacent ones of thefirst segments for a second length, and include a second texture and asecond cross-sectional dimension. The second texture is substantiallydissimilar from the first texture, and the second cross-sectionaldimension is substantially dissimilar from the first cross-sectionaldimension. The thread includes alternating ones of the first and secondsegments.

In other embodiments, the invention provides a method of making dentalfloss that includes applying tension to a length of thread to therebyreduce at least one cross-sectional dimension of the length of thread. Aportion of the tensioned length of thread is bonded, the tension isreleased from the length of thread such that the bonded portion of thelength of thread maintains the reduced cross-sectional dimension.

In still other embodiments, the invention provides a method of makingmulti-texture dental floss that includes unwinding a length of threadfrom a feed spool and feeding the length of thread through first feedrollers. The length of thread is fed from the first feed rollers tofirst tensioning rollers, and wound about a drum to apply tension to thelength of thread. Applying tension to the length of thread reduces atleast one cross sectional dimension of the length of thread. A portionof the tensioned length of thread is bonded by applying an adhesive,which is allowed at least partially to cure while the thread is woundupon the drum. The tension is released from the length of thread byunwinding the thread from the drum to second tensioning rollers, and thelength of thread is fed from the second tensioning rollers to secondfeed rollers. The length of thread is also wound onto a take-up spool.

In some embodiments, the invention provides a dental floss dispensingunit, the dispensing unit including a housing and a supply spool coupledto the housing and having a length of floss wound thereabout. The supplyspool having a locked position, where the supply spool is fixed withrespect to the housing, and an unlocked position, where the supply spoolis free to rotate with respect to the housing.

In other embodiments, the invention provides a dental floss dispensingunit, the dispensing unit including a housing and a length of floss inthe housing. The length of floss including first portions and secondportions, the first portions having a different stiffness than thesecond portions. The dispensing unit also includes a locking mechanismengaging the floss and changing between a locked configuration and anunlocked configuration depending upon whether the locking mechanism isengaged with one of the first portions or one of the second portions.

In still other embodiments, the invention provides a dental flossdispensing unit, the dispensing unit including a housing and a length offloss in the housing. The length of floss having first portions andsecond portions of differing stiffness. The floss dispensing unit alsoincludes a locking mechanism engaging the floss and changing from anunlocked configuration to a locked configuration in response towithdrawal of a predetermined length of floss from the housing.

In still other embodiments, the invention provides a dental flossdispensing unit, the dispensing unit including a housing and a supplyspool rotatable with respect to the housing and having a length of flosswound thereabout. The dispensing unit also including a locking mechanismfor dispensing a predetermined amount of floss from the housingindependently of rotation of the supply spool.

In some embodiments, a dental floss dispensing unit includes a housing,a supply spool, and a metering element. The supply spool is coupled tothe housing and has a length of floss wound thereabout. The length offloss includes a free end extending from the housing. The meteringelement is coupled to the housing and operatively engages a portion ofthe length of floss. The metering element provides resistance againstremoval of the length of floss from the housing, and a magnitude of theresistance against removal of the length of floss from the housing isdependent upon at least one property of the portion of the length offloss engaging the metering element.

In other embodiments, a dental floss dispensing unit includes a housing,a supply spool, and a metering element. The supply spool is coupled tothe housing and has a length of floss wound thereabout. The length offloss has a plurality of alternating and distinct first and second flosssegments. The metering element engages the length of floss and providesresistance to removal of the length of floss from the housing. Amagnitude of the resistance changes as each floss segment moves intoengagement with the metering element.

In still other embodiments, a dental floss dispensing unit includes ahousing that defines an interior volume and an opening communicatingwith the volume. A length of dental floss is contained by the volume andhas a free end extending through the opening. The length of dental flossincludes a plurality of alternating first and second segments. The firstsegments have a first physical property and the second segments have asecond physical property that is different from the first physicalproperty. The housing provides a tactilely detectable indexing asalternating first and second segments are withdrawn from the housing.

In still other embodiments, a dental floss dispensing unit includes ahousing defining a volume and a supply spool carried by the housing andpositioned within the volume. A length of floss is wound about thesupply spool and has a free end extending from the housing. The free endcan be pulled to unwind floss from the supply spool, and withoutmanipulating the housing the supply spool is manually rotatable torewind floss onto the supply spool.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a length of multi-texture dental floss embodying theinvention.

FIG. 2 is an enlarged view of portions of the multi-texture dental flossof FIG. 1.

FIG. 3 is a schematic view of a method for manufacturing themulti-texture dental floss of FIG. 1.

FIG. 4 is a schematic view of an alternate method of manufacturing themulti-texture dental floss of FIG. 1.

FIG. 5 is a perspective view of a dispenser for the multi-texture dentalfloss of FIG. 1.

FIG. 6 is a perspective view of a manufacturing assembly formanufacturing a multi-texture dental floss.

FIG. 7 is a schematic diagram of the manufacturing assembly of FIG. 6.

FIGS. 8 a-e illustrate an alternate construction of a dispenser for themulti-texture dental floss of FIG. 1.

FIG. 9 is a section view take along line 9-9 in FIG. 8 a.

FIGS. 10 a-10 b illustrate a housing of the dispenser of FIG. 8 a.

FIG. 11 is a section view taken along line 11-11 of FIG. 10 a.

FIG. 12 is a section view taken along line 12-12 of FIG. 10 a.

FIG. 13 is a section view taken along line 13-13 of FIG. 10 a.

FIGS. 14 a-14 d illustrate a window panel of the dispenser of FIG. 8 a.

FIG. 15 is a section view taken along line 15-15 of FIG. 14 a.

FIG. 16 is a section view taken along line 16-16 of FIG. 14 a.

FIGS. 17 a-17 b illustrate a roller of the dispenser of FIG. 8 a.

FIG. 18 is a section view taken along line 18-18 of FIG. 17 a.

FIGS. 19 a-19 c illustrate a supply spool of the dispenser of FIG. 8 a.

FIG. 20 is a section view taken along line 20-20 of FIG. 19 a.

FIG. 21 is a section view taken along line 21-21 of FIG. 19 b.

FIGS. 22 a-22 d illustrate a carriage of the dispenser of FIG. 8 a.

FIG. 23 is a section view taken along line 23-23 of FIG. 22 a.

FIG. 24 is a section view taken along line 24-24 of FIG. 22 a.

FIGS. 25 a-25 d illustrate a disk of the dispenser of FIG. 8 a.

FIG. 26 is a section view taken along line 26-26 of FIG. 25 a.

FIG. 27 is a front view of the dispenser of FIG. 8 a with the frontportion and the supply spool removed to show the carriage in a firstposition.

FIG. 28 is a front view of the dispenser of FIG. 8 a with the frontportion and the supply spool removed to show the carriage in a secondposition.

FIGS. 29 a-29 e illustrate a reset button of the dispenser of FIG. 8 a.

FIG. 30 is a front view of the dispenser of FIG. 8 a with the frontportion removed and the carriage in a first position.

FIG. 31 is a front view of the dispenser of FIG. 8 a with the frontportion removed and the carriage in a second position.

FIG. 32 is a front view of the dispenser of FIG. 8 a with the coverportion in an open position.

FIG. 33 is a front view of the dispenser of FIG. 8 a with the coverportion in a closed position.

FIGS. 34-38 illustrate an alternate construction of a dispenser for themulti-texture dental floss of FIG. 1.

FIG. 39 is a section view taken along line 39-39 of FIG. 34.

FIG. 40 shows the dispenser of FIG. 34 with the housing opened.

FIG. 41 is a side view of the dispenser of FIG. 40.

FIG. 42 is a section view taken along line 42-42 of FIG. 40.

FIG. 43 shows the dispenser of FIG. 34 with the front portion removed.

FIGS. 44-48 illustrate an alternate construction of the supply spool.

FIG. 49 is a front view an alternate construction of a dispenser for themulti-texture dental floss of FIG. 1.

FIG. 50 illustrates the dispenser of FIG. 49 with the housing in an openposition.

FIG. 51 illustrates the dispenser of FIG. 49 with the front portionremoved.

Before at least one embodiment of the invention is explained in detail,it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangements of thecomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments and of beingpracticed or being carried out in various ways.

DETAILED DESCRIPTION

FIG. 1 illustrates a length of multi-texture dental floss 10 embodyingthe invention. The floss 10 is comprised of alternating segments offloss 14 a and 14 b having different textures. In the illustratedembodiment, the segments 14 a are relatively smooth, while the segments14 b are textured. The segments 14 a are configured to more easily fitinto the spaces between teeth, while the segments 14 b are configured tomore effectively remove plaque and debris from the spaces between teeth.The length of floss 10 illustrated in FIG. 1 represents only a portionof a larger length of floss that may be wound onto a spool for storageand dispensing, as discussed further below.

With reference also to FIG. 2, in some embodiments, the segments 14 amay have a thickness in at least one direction that is less than athickness of the textured segments 14 b. For example, the segment 14 amay have a thickness in at least one direction of approximately 0.5 mmor less, while the segment 14 b may have a thickness in at least onedirection of approximately 1 mm or more. In some instances, the segment14 a will have a thickness less than the segment 14 b in only onedirection. For example, the segment 14 a may be formed substantially asa ribbon, having one relatively small cross-sectional dimension, andanother relatively large cross-sectional dimension. In such cases, thelarger cross-sectional dimension may be substantially equal to across-sectional dimension of the segment 14 b.

The segment 14 b may also be formed substantially as a ribbon but willgenerally include a minimum cross-sectional dimension that is largerthan the minimum cross-sectional dimension of the segment 14 a.Furthermore, while the segment 14 a is generally provided with a smoothsurface texture to ease manipulation of the floss into the space betweenteeth, the segment 14 b is generally provided with a textured surface tomore effectively remove plaque and other debris from the space betweenthe teeth. The textured surface may be a result of tightly weaving flossfibers in a way that provides peaks and valleys within the floss, or maybe the result of a relatively loose weave that provides a generallycircular cross section defined by relatively soft and compliant fibers.Generally speaking, the segments 14 a have in common a certain propertythat distinguishes the segments 14 a from the segments 14 b, which alsohave a certain property in common. For example, the segment 14 a may befabricated in a manner that results in the segment 14 a being more stiffthan the segment 14 b. In this regard, the end of a segment 14 a can beused to thread a length of floss 10 “end first” into an interdentalspace, rather than manipulating a central portion of the floss upwardlyor downwardly into the space between adjacent teeth. This feature may beparticularly helpful for individuals with dental appliances or bracesbecause it allows the floss to be inserted between the dental applianceor braces and the gum line.

FIG. 3 schematically illustrates a first method for making theabove-described multi-texture floss 10. The method includes applyingtension to a length of floss 22 and winding the taught length of floss22 around a drum 26. Applying tension to the floss 22 reduces thecross-sectional area and corresponding cross-sectional dimensions of thefloss 22. The tension also draws individual floss fibers more closelytogether, thereby smoothing peaks and valleys that may be present in,for example, a woven floss.

More specifically, the method utilizes a feed spool 23 wound with asupply of uncoated or otherwise untreated floss fiber. The length offloss 22 is uncoiled from the feed spool 23 by a pair of feed rollers24. The feed rollers 24 then position the floss 22 to be received byfirst tensioning rollers 25. The first tensioning rollers 25 arepreferably rotated by a driving device (e.g. motor, not shown) anddirect the length of floss 22 onto the drum 26. The speed of the firsttensioning rollers 25 is adjusted so that the length of floss 22 ispulled taught and brought under tension as it is wound onto the drum 26.

The drum 26 is selected to have a circumference that is substantiallyequal to the desired length of floss that will include at least onesmooth segment 14 a and at least one textured segment 14 b of thefinished multi-texture floss 10. After a suitable length of taut floss22 has been wound around the drum, an adhesive is applied to a section30 of the drum 26 and thus to the floss 22 by rolling, spraying, orotherwise applying the adhesive in an axial direction from one end ofthe drum 26 to the other. One example of a suitable adhesive includescyanoacrylate, however other adhesives may also be used. In someembodiments, the adhesive is applied to the drum 26 and floss 22 in anapproximately one to two inch wide strip. In the illustratedconstruction, the section 30 includes an axially-extending channel intowhich the adhesive may be sprayed. By spraying the adhesive into achannel the adhesive can be applied uniformly about the exposed outersurfaces of the length of floss 22.

After the adhesive has set, the floss 22 is unwound from the drum 26.The floss 22 then passes through second tension rollers 27. The secondtension rollers 27 are preferably rotated by a driving device (e.g.,motor, not shown) at an adjustable speed to maintain the tension in thefloss 22. After passing through the second tension rollers 27, thetension that was previously applied to the floss to reduce itscross-sectional area is relieved and the sections of floss that did notreceive adhesive return to their original size, shape, and texture.These sections become the textured sections 14 b of the finishedmulti-texture floss 10. However, the portions of the floss 22 to whichthe adhesive was applied maintain the reduced cross-sectional area andreduced cross-sectional dimensions provided by applying tension to thefloss, and the surface of the floss is more uniform than beforeprocessing as a result of the bonding and smoothing properties providedby the adhesive. These portions become the smooth segment 14 a of thefinished multi-texture floss 10. The floss 22 then passes through feedrollers 28 that position the floss 22 for coiling on a take-up spool 29.The take-up spool 29 is generally cylindrical and includes an outerdiameter 31. The outer diameter 31 is selected to be relatively large sothat as the floss 22 continues to cure, it takes on a more linearconfiguration.

In some embodiments, as the finished floss 10 is unwound from thetake-up spool 29, it may be coated under light tension on standardcoating equipment in a second manufacturing operation. Such coatings mayinclude paraffin wax, vinapas, liquid nylon, polyethylene glycol,flavoring, or coloring. In yet other embodiments, the finished floss 10may be packaged into spools, such as the spools discussed below, or maybe cut to length and packaged as individual strands having at least oneeach of a smooth segment 14 a and a textured segment 14 b. In yetanother embodiment, the floss may undergo the light tension coatingprocedure before being wound onto the take-up spool 29 as an additionalstep of the multi-texturing process.

It should be appreciated that instead of applying a single strip ofadhesive to the floss 22 wound upon the drum 26, multiple strips ofadhesive could also be applied, resulting in multiple smooth andtextured segments 14 a, 14 b for each individual winding of floss 22. Inthis regard, the circumference of the drum 26 and the number of adhesiveapplications may be selected to meet the demands of a particularmanufacturing process.

FIG. 4 illustrates another method for making the above-describedmulti-texture floss 10 including the use of sonic welding. In thismethod, a length 22 a of uncoated or otherwise untreated floss isunwound from a feed spool 23 a. The floss is then fed through first feedrollers 24 a and first tension rollers 25 a similar to the uncoiling andfeeding steps described above. In the embodiment of FIG. 4, the firsttension rollers 25 a cooperate with second tension rollers 27 a suchthat the floss extending between the first and second tension rollers 25a, 27 a is under tension, thereby reducing its cross-sectional area andcross-sectional dimensions as described above. The tensioned length offloss 22 a is advanced between first and second dies 50 a, b of a sonicwelding device 52. The first and second dies 50 a, b are closed and theportion of the floss between the dies is sonically welded. The sonicwelding bonds the floss fibers together such that, once tension on thefloss is removed by advancing the floss past the second tension rollers27 a, the sonically welded portion of floss maintains its reducedcross-sectional area and reduced cross-sectional dimensions. Thesonically welded portion of floss thereafter form a smooth segment 14 aof the finished multi-texture floss 10, and the untreated portions offloss on either side of the sonically welded portion of floss becometextured segments 14 b of the finished multi-texture floss 10. Thelength of the smooth segment 14 a will substantially correspond to thesize of the dies 50 a, b. In some embodiments, the smooth segments 14 ahave a length of between about one and two inches.

After forming one smooth segment 14 a, the length of floss is advancedto position a new portion of floss between the dies of the sonic weldingdevice. The length of the textured segments 14 b can be adjusted byadvancing the floss by varying amounts through the rollers 25 a, 27 abetween welding operations. As with the method described above, thefloss 22 passes through a pair of feed rollers 28 a that position thefloss 22 a for coiling on a take-up spool 29 a. The take-up spool 29 ais generally cylindrical and includes an outer diameter 31 a. The floss22 a may similarly be coated under light tension on standard coatingequipment in a second manufacturing operation. Such coatings may includeparaffin wax, minapause, flavoring, and/or coloring. In yet otherembodiments, the finished floss 10 may be packaged into spools, such asthe spools discussed below, or may be cut to length and packaged asindividual strands having at least one each of a smooth segment 14 a anda textured segment 14 b. In yet another embodiment, the floss mayundergo the light tension coating procedure before being wound onto thetake-up spool 29 a as an additional step of the multi-texturing process.

Examples of known flosses that may be manufactured using the methodsdescribed above to create the multi-textured floss 10 include GUM® brandButler Weave® floss, GUM® brand Expanding Floss, GUM® brand Eez-Thru®floss, and GUM® brand waxed or unwaxed flosses. These and other suitableflosses may be made from one or more materials such as nylon,polytetrafluoroethylene (PTFE), ultra-high molecular weight polyethylene(UHMWPE), and polyester, among others.

For example, GUM® brand Butler Weave® floss is a braided nylon dentalfloss of approximately 840 denier that may be waxed or unwaxed. GUM®brand Expanding Floss is a twisted waxed nylon dental floss ofapproximately 700 denier that, when untreated, expands when abraded orupon contact with moisture during use. When treated to createmulti-texture floss 10 using one of the methods described above, onlythe textured segment 40 of the Expanding Floss will expand during use.GUM® brand Eez-Thru® floss is a monofilament of polytetrafluoroethylene(PTFE) of between about 810 and 990 denier. GUM® brand waxed or unwaxedflosses are formed of twisted, shred resistant fine nylon ofapproximately 700 denier.

FIG. 5 illustrates a dispenser 34 for the multi-texture floss 10. Whilevarious configurations are possible, the illustrated dispenser 34includes a body 38 and a cover 42. The body 38 rotatably supports aspool (not shown) upon which a length of floss 10 having a plurality ofsegments 14 a, 14 b is wound. Because the smooth segments 14 a tend toretain the shape of the spool onto which they are wound, the spoolpreferably has a diameter that is greater than the diameter oftraditional dental floss spools. In this way, the curvature of thesmooth segments 14 a once removed from the spool is reduced.

The body 38 also defines an opening 46 through which the floss 10 can bedispensed. The opening 46 may include, among other things, a reducedaperture, a flap portion biased against the floss, or a detentarrangement to provide a tactilely detectable indexing of the floss asthe alternating smooth segments 14 a and textured segments 14 b arewithdrawn from the body 38 and pass through the opening 46. Flosscutting and floss retention tabs (not shown) may also be provided on thebody 38, or the floss may be severed and retained by structure providedon the cover 42 when the cover 42 is closed against the body 38.

FIG. 6 illustrates a manufacturing assembly 50 capable of performing yetanother method for manufacturing multi-texture floss, such as themulti-texture floss 10. FIG. 7 is a schematic diagram depicting certaincomponents of the manufacturing assembly 50. The manufacturing assembly50 includes a spine or frame 54 to which the various components of theassembly 50 are coupled. The frame 54 may be fabricated from anysuitable material, such as various steel or aluminum alloys, and in someembodiments may be formed from commercially-available channel track thatallows for rapid mounting and adjustment of the components along theframe 54. In other embodiments, the components may be mounted toindividual frames or other structures.

Moving from left to right in FIGS. 6 and 7, the assembly 50 includes anunwind spool 58, a tensioning device 62, a tension transducer 66, anadhesive dispensing assembly 70, a curing section 72, a drive assembly74, a spooling dancer arm 78, and a wind up spool 82. In the illustratedembodiment, the unwind spool 58, tensioning device 62, tensiontransducer 66, adhesive dispensing assembly 70, drive assembly 74,spooling dancer arm 78, and wind up spool 82 are each mounted to theframe 54. The assembly 50 also includes a control assembly 86 (FIG. 6)that may or may not be mounted to the frame 54. In some embodiments, thecuring section 72 may include an optional curing station 90 (FIG. 7) forcuring certain compounds that may be applied to the floss.

The unwind spool 58 carries a bulk quantity of floss 94 that typicallybut not necessarily is a substantially uniform, single-texture floss.For example, the floss 94 carried on the unwind spool 58 may be orinclude one or more of the specific floss types or brands identifiedabove. The unwind spool 58 is mounted for rotation about an axis 98. Inthe illustrated embodiment the axis 98 is horizontal, but in otherembodiments the axis 98 may be vertical (e.g., similar to a turn table),or at an angle between horizontal and vertical. The unwind spool 58 canbe mounted upon any suitable supports, and may include a tensioningmechanism (not shown) that resists slightly the unwinding of floss 94from the unwind spool 58. The tensioning mechanism can be used toprevent the rotational momentum of the unwind spool 58 from continuingto unwind floss when the assembly 50 slows or stops. The unwind spool 58generally is not driven by its own motor or actuator, but insteadrotates to unwind the floss 94 in response to pulling forces applied tothe floss 94 by other components of the assembly 50.

As indicated by the dashed line of FIG. 7, the floss 94 unwinds from theunwind spool 58 and extends to and through the tensioning device 62. Thetensioning device 62 may take on a variety of forms, but generallyincludes a cylinder 102 (FIG. 6) or pair of cylinders 102 (FIG. 7)around and/or between which the floss 94 extends. The followingdescription refers to a tensioning device 62 having a single cylinder102, however the similar principles apply to a tensioning device 62having two or more cylinders 102. The cylinder 102 is rotatably mountedsuch that, as the floss is drawn around the cylinder 102, the cylinder102 rotates. To apply tension to the floss 94, the rotatable mounting ofthe cylinder 102 does not allow for free or substantially free rotationof the cylinder 102. Rather, cylinder 102 is mounted in a way thatprovides a controlled resistance to rotation. In some embodiments, theresistance to rotation may be substantially constant. In otherembodiments, the resistance to rotation may be adjustable, therebyallowing for adjustments in the amount of tension applied to the floss.In some embodiments with adjustable resistance to rotation, theadjustment may be automatically controllable by way of the controlassembly 86, as described further below. The tensioning device 62applies tension to the floss 94 such that, as discussed above, at leastone cross sectional dimension of the floss 94 is reduced. Generallyspeaking, the greater the tension on the floss 94, the greater thereduction in the at least one cross sectional dimension.

After passing through the tensioning device 62, the floss 94 passesthrough the tension transducer 66. In the illustrated embodiment, thetension transducer 66 includes three spaced-apart rollers 106 thattogether define a serpentine path along which the floss 94 extends. Thetension transducer 66 includes a suitable sensor, such as one or morestrain gauges or other displacement sensor(s) (not shown), that measuresthe displacement of the middle roller due to the floss 94 extendingalong the serpentine path between the rollers 106. The higher thetension on the floss 94, the greater the displacement of the middleroller 106. As the use of strain gauges suggests, the displacement ofthe middle roller 106 may be extremely small. Signals from the sensormay be processed internally by the tension transducer 66 andcommunicated to the control assembly 86, or unprocessed or “raw” signalsfrom the sensor(s) within the tension transducer 66 may be communicateddirectly to the control assembly 86, and the control assembly 86 maythen perform suitable signal processing. In either case, signalscorresponding the amount of tension in the floss 94 are communicated tothe control assembly 86 so suitable adjustments may be made by anoperator or by the control assembly 86 itself. In one exemplaryembodiment, the tension in the floss 94 is maintained between about 100and 400 grams.

After passing through the tension transducer 66, the floss 94, whileremaining under tension, passes through the adhesive dispensing assembly70. In the illustrated embodiment, the adhesive dispensing assembly 70includes a coating die 110, a control valve 114 that regulates thesupply of adhesive to the coating die 110, and an adhesive supply 118.With reference primarily to FIG. 7, the coating die 110 includes a flosspassageway 122 through which the floss 94 extends, and a supplypassageway 126 that intersects the floss passageway 122 and deliversadhesive to the floss passageway 122. The supply passageway 126 alsocommunicates with the control valve 114, which operates tointermittently supply adhesive to the supply passageway 126 and thefloss passageway 122 for application of adhesive to the floss. Thecontrol valve 114 receives adhesive from the adhesive supply 118. As thefloss 94 passes through the floss passageway 122 portions of the flosscollect, e.g., are coated with, the adhesive that is intermittentlysupplied to the floss passageway 122 by way of the supply passageway 126and the control valve 114.

The adhesive supply 118 may be or include, without limitation, a bulkvolume of adhesive, such as an elevated storage tank, a pressurized linecontaining adhesive, or any combination of these or other suitablevolumes and/or conduits for supplying adhesive to the control valve 114and coating die 110. The control valve 114 may be or include a solenoidoperated valve or other suitable valve that is capable of controlled,intermittent operation between on and off positions. As discussedfurther below, the control valve 114 operates to intermittently supplyadhesive to the supply passageway 126 and the floss passageway 122 suchthat, as the floss 94 is drawn through the floss passageway 122,adhesive is intermittently applied to spaced-apart segments of the floss94. In this way, some segments of floss receive adhesive, and othersegments of floss do not receive adhesive. With reference also to FIGS.1 and 2, the segments of floss that receive adhesive while passingthrough the adhesive dispensing assembly 70 correspond to the relativelysmooth segments of floss 14 a, while the segments of floss that do notreceive adhesive while passing through the adhesive dispensing assembly70 correspond to the textured segments 14 b of floss 10.

After passing through the adhesive dispensing assembly 70, the floss 94travels along a curing section 72 for curing of the adhesive that hasbeen applied to segments of the floss 94. As shown in FIG. 6, the curingsection 72 extends between the adhesive dispensing assembly 70 and thedrive assembly 74, and comprises a relatively large portion of theoverall length of the assembly 50. For example, in the exemplaryembodiment of FIG. 6, the curing section 72 is longer than the distancebetween the unwind spool 58 and the adhesive dispensing assembly 70. Theextended length of the curing section 72 allows the adhesive applied tothe floss 94 by the adhesive dispensing assembly 70 to cure before thefloss 94 arrives at the drive assembly 74.

A variety of suitable adhesives or combinations of adhesives may beapplied by the adhesive dispensing assembly 70 or, in some embodiments,by two or more adhesive dispensing assemblies 70 (e.g., for applicationof multi-part adhesives). For example, the embodiment of FIG. 6 uses anair cure cyanoacrylate that cures sufficiently in the time it takes thefloss to travel from the adhesive dispensing assembly 70 to the driveassembly 74. Other embodiments may utilize adhesives that are cured byway of exposure to certain types of light (e.g., UV light), heat, orother environments, without limitation. Such embodiments may include theoptional curing station 90 illustrated in FIG. 7. The optional curingstation 90 may be or include lights, heating elements, or other devicesthat expose the adhesive to whatever environment is necessary to curethe adhesive.

After passing through the curing section 72 the floss 94 arrives at thedrive assembly 74. In the illustrated embodiments, the drive assembly 74is a variable speed drive assembly, the speed of which can be controlledby the control assembly 86. The illustrated drive assembly 74 includes amotor 128, which may be electric, hydraulic, pneumatic, or the like, adrive unit 130 coupled to the motor 128, and a drum 134 coupled to thedrive unit 130. The motor 128, in combination with the drive unit 130,is operable to rotate the drum 134 at a desired speed. The drum 134includes an outer cylindrical surface 138 having a circumference thatcorresponds to a desired length of a single floss fragment, which in thepresent invention includes the combined length of a single smoothsegment of floss 14 a and a single textured segment 14 b of floss 10(see FIG. 1).

The floss 94 is wound for one revolution about the outer cylindricalsurface 138. Rotation of the drum 134 by the motor 128 and drive unit130 pulls the floss 94 off of the unwind spool 58 and through thetensioning device 62. As such, the entire length of floss extendingbetween the tensioning device 62 and the drive assembly 74, includingthe floss extending through the tension transducer 66 and the adhesivedispensing assembly 70, is under tension, thereby reducing at least onecross sectional dimension of the floss 94, as discussed above. After thefloss 94 travels around the drum 134, the tension on the floss 94 isreduced or eliminated, thereby allowing the segments of floss that didnot receive an application of adhesive to relax, which results in anincrease of the at least one cross sectional dimension of the floss 94for those segments.

In the illustrated embodiment, the drum 134 also functions as an encoderwheel that regulates the operation of the adhesive dispensing assembly70. As shown in FIG. 6, an arcuate sensor plate 142 is coupled to a sidesurface of the drum 134 for rotation therewith, and a sensor 146 ispositioned adjacent the side surface and along the outer circumferenceof the drum 134, but is fixed relative to the frame 54. The sensor 146is operable to sense the presence or absence of the sensor plate 142 asthe drum 134 rotates, and communicates with the control assembly 86. Thecontrol assembly 86, in turn, operates the control valve 114 of theadhesive dispensing assembly 70 in response to signals received from thesensor 146. Specifically, in the illustrated embodiments when the sensorplate 142 is not positioned in front of the sensor 146, the controlassembly 86 turns the control valve 114 off such that adhesive is notapplied to the floss 94. When the sensor plate 142 is positioned infront of the sensor 146, the control assembly 86 turns the control valve114 on such that adhesive is applied to the floss 94. In someconstructions, multiple drive assemblies 74, each controlling anindividual adhesive dispensing assembly, may be present.

The sensor plate 142 has an arc length approximately equal to thedesired length of a single smooth segment of floss 14 a. In theillustrated construction, this arc length is about one-fourth of thetotal circumference of the drum. As discussed above, the circumferenceof the drum 134 corresponds to the desired combined length of a singlesmooth segment of floss 14 a and a single textured segment 14 b of floss10 (e.g., a floss fragment). Thus, in the illustrated embodiment, thelength of a smooth segment of floss 14 a (e.g., floss to which adhesivehas been applied while the floss is under tension) will be equal toabout one-third of the total length of a textured segment 14 b of floss10 (e.g., floss to which no adhesive has been applied). Of course, therelative lengths of the smooth segment 14 a and textured segment 14 b offloss may vary depending upon the desired configuration of the finishedfloss 94.

Since the drum 134 doubles as both a drive unit and an encoder wheel,the operation of the control valve 114 automatically adjusts inproportion with the speed of the drive unit 130. As such, any change inthe speed of the drum 134 results in a proportional change in thefrequency and duration that adhesive is applied to the floss 94 as itpasses through the adhesive dispensing assembly 70. Therefore the lengthof the smooth segment 14 a and the proportions between the smooth andtextured segments (e.g., 1:3) are maintained.

During operation, the size, number, and position of the smooth segments14 a within a given floss fragment can be adjusted by altering the size,quantity, and position of the sensor plates 142 along the circumferenceof the drum 134. More specifically, increasing the arcuate length of aparticular sensor plate 142 will increase the duration that adhesivewill be applied to the floss 94, increasing the length of thatparticular smooth segment 14 a. Furthermore, adding, removing, oraltering the location of each sensor plate 142 with respect to othersensor plates 142 will modify the number and relative position of eachsmooth segment of floss 14 a in a particular floss fragment. Inconstructions where more than one sensor plate 142 is present, alteringthe distance between the two plates 142 can also be used to establishthe length of the texture segments 14 b.

After passing through the drive assembly 74 the floss 94 arrives at thespooling dancer arm 78. The spooling dancer arm 78 directs the floss 94onto the wind-up spool 82 as it travels from the drive assembly 74.Illustrated in FIG. 6, the dancer arm 78 includes a motor, actuator,drive screw, or the like (not shown) driving a swing arm 150 that pivotsfrom side to side so the floss 94 winds onto the wind-up spool 82 in adesired pattern (e.g., evenly, tapered, or the like). The swing arm 150includes an aperture 154 through which the floss 94 passes, allowing theswing arm 150 to determine the axial position along the spool 82 thatthe floss 94 will be wound.

In alternate constructions, the spooling dancer arm 78 may not pivot butinstead traverse along a drive screw or rotate about an axis. In stillother constructions, the spooling dancer arm 78 may include a stationaryaperture through which the floss 94 passes while the wind-up spool 82 ismoved axially to alter the position that the floss 94 will be wound.

After passing through the spooling dancer arm 78, the floss is woundabout the wind-up spool 82. The wind-up spool 82 carries the finishedfloss 94, and may define an outer diameter that is generally greaterthan that of a standard spool used to store floss to minimize thecurvature of the floss as it is removed from the spool 82. The wind-upspool 82 is mounted for rotation about an axis 158. In the illustratedembodiment the axis 158 is horizontal, but in other embodiments the axis158 may be vertical (e.g., similar to a turn table), or at an anglebetween horizontal and vertical. The wind-up spool 82 can be mountedupon any suitable supports, and includes a motor 162 to rotate the spool82. The motor 162 provides the tension in the floss 94 after it has leftthe drive assembly 74, pulling the floss 94 through the spooling dancerarm 78 and onto the wind-up spool 82 for final storage.

FIGS. 8 a-33 illustrate an embodiment of a floss dispenser 300 fordispensing the multi-texture floss 10. The floss dispenser 300 containsa supply of floss 304 (see FIG. 9) and generally controls the amount offloss 10 that can be removed from the dispenser 300 at any one time. Thefloss dispenser 300 includes a housing 308, a supply spool 312 rotatablysupported by the housing 308 and having the floss supply 304 woundthereabout, and a locking mechanism 316 that engages the floss 10 tocontrol the release of floss from the housing 308.

More specifically, the floss dispenser 300 is configured to dispense asingle flossing fragment 320 (see FIG. 1) from the housing 308 each timethe user operates the dispenser 300. Once a flossing fragment 320 hasbeen removed from the housing 308, the locking mechanism 316 restrictsthe removal of additional floss 10 from the floss supply 304 (e.g., bypreventing rotation of the supply spool 312). Thereafter, the flossdispenser 300 typically remains in a locked configuration until a resetcondition is met, such as actuating a reset button, closing a cover, orthe like. When the reset condition is met, the locking mechanism 316returns to its initial configuration and an additional flossing fragment320 may be removed by the user.

In the present description, a flossing fragment 320 is a length of floss10 having a certain desired property or properties. The desiredproperties of the fragment 320 may include, but are not limited to, aparticular length, a given number or sequence of segments (e.g., acombination of smooth and textured segments 14 a, 14 b), a given numberor sequence of portions with a particular stiffness, or the like. Forpurposes of the following description, each flossing fragment 320includes a leader 324, a center section or body 328, and a tail 332,where the leader and tail 324, 332 are formed by smooth segments 14 a ofthe multi-texture floss 10 and the body 328 is formed by a texturedsegment 14 b of the multi-texture floss 10 (see FIG. 1). Thisconfiguration is achieved by cutting each smooth segment 14 a such thatone portion of the cut smooth segment 14 a becomes the leader 324, andthe other portion of the cut smooth segment 14 a becomes the tail 332.

Illustrated in FIGS. 8 a-13, the housing 308 of the floss dispenser 300includes a substantially flat bottom surface 336 configured to rest on asupport surface (e.g., a table top) and curvilinear walls that taper toa rounded point as they extend upwardly from the bottom surface 336 todefine a storage volume 340. The housing 308 includes a first or frontportion 344, a second or rear portion 348, and a cap portion 352. Thehousing 308 also includes a window panel 356 coupled to the frontportion 344. In the illustrated construction, the front and rearportions 344, 348 are pivotably coupled to one another by a hinge member360 (see FIG. 10 a), such that the portions 344, 348 can be pivoted intoand out of engagement with one another during assembly or for replacingthe floss supply 304. In the present invention, the portions 344, 348 ofthe housing 308 are formed as a single piece of material (e.g., moldedplastic) however, in alternate constructions, the portions 344, 348 maybe formed individually.

Illustrated in FIGS. 10 a-11, and 13, the front portion 344 of thehousing 308 includes a bottom wall 364, a top wall 368 oriented at anangle to and spaced a distance from the bottom wall 364, and a frontwall 372 extending between the top and bottom walls 368, 364. Bestillustrated in FIG. 13, the front portion 344 also includes an alignmentridge 384 extending along at least a portion of the periphery 376 of thefront portion 344. The alignment ridge 384 provides rigidity to theassembled housing 308 and aligns the front portion 344 with the rearportion 348 during assembly.

The front portion 344 of the housing 308 also includes a plurality ofalignment recesses 388 b configured to receive alignment pins 388 aformed on the rear portion 348. When the front portion 344 and rearportion 348 are joined together, each alignment pin 388 a of the rearportion 348 aligns with and is received by a corresponding alignmentrecess 388 b of the front portion 344. The alignment pins 388 a andrecesses 388 b align the front and rear portions 344, 348 of the housing308 to aid assembly of the floss dispenser 300. In some constructions,the alignment pins 388 a and alignment recess 388 b are configured foran interference fit, thereby aiding in coupling the two portions 344,348 to one another. In other constructions, locking tabs, adhesives, orother forms of coupling (not shown) may be used to couple the frontportion 344 and the rear portion 348. In still other constructions,alignment pins 388 a may be provided on the front portion 344, andalignment recesses 388 b may be provided on the rear portion 348.

The bottom wall 364 of the front portion 344 is substantiallysemi-elliptical in shape, having a curvilinear edge that at leastpartially defines the contour of the front wall 372. The bottom wall 364is substantially planar, being configured to rest upon a support surface(e.g., a table top) and maintain the floss dispenser 300 in asubstantially vertical orientation. In some constructions, the bottomwall 364 may include feet or be coated in a high friction material(e.g., rubber) to help stabilize the floss dispenser 300 on the supportsurface.

The top wall 368 of the front portion 344 is generally semi-ellipticalin shape and is positioned at an angle with respect to the bottom wall364. The top wall 368 includes a curvilinear edge that is recessedslightly inwardly from the front wall 372 so the cap portion 352 isflush with the housing 308 when the cap portion 352 is in the closedposition (see FIG. 9). The top wall 368 also includes a depression 400,extending into the housing 308, to provide a space for the user'sfingers when grasping the floss 10.

The top wall 368 of the front portion 344 also defines a graduallytapering slot 404 extending inwardly from the periphery 376 (see FIG. 10b). When the housing 308 is assembled, the slot 404 is aligned with andreceives a tapered projection 408 that extends from the periphery of theof the rear portion 348 to define an opening 412 through which the floss10 can be dispensed. In some constructions, the opening 412 may includea resilient flap or other detent arrangement (not shown) to restrict themovement of the floss 10 to a single direction.

The top wall 368 also includes a cutting member 416 (see FIG. 32). Thecutting member 416 is positioned on the top wall 368 opposite theopening 412 with the depression 400 positioned therebetween. The cuttingmember 416 is configured to sever or cut the dispensed floss fragment320 from the floss supply 304 so it can be utilized by the user. In theillustrated construction, when the floss fragment 320 is cut from thefloss supply 304 end portion 420 of the floss supply 304 is held orpinched within the cutting member 416 where it is held in place forsubsequent use.

In the illustrated construction, the cutting member 416 is formedseparately from the top wall 368, and may be stamped from a piece ofsheet material (e.g., steel). The cutting member 416 includes a C-shapedclip portion able to clasp onto the top wall 368 to position a cuttingtab in an appropriate position. In other constructions, the cuttingmember 416 may be molded into the housing 308 or adhered to the top wall368 by an adhesive.

As shown in FIGS. 10 a, 11, and 13, the front portion 344 also defines awindow recess 424 that receives the window panel 356 (see FIGS. 14a-16). The window recess 424 is at least partially defined by the frontwall 372 and permits the user to observe the amount of floss 10remaining in the floss supply 304. In the illustrated construction, thewindow recess 424 includes a combination of lips, grooves, and lockingtabs 428 that extend along at least a portion of the periphery of therecess 424 to secure the window panel 356 within the recess 424.

As shown in FIG. 8 e, the front portion 344 defines a notch 432 that isrecessed relative to the periphery 376 proximate the top wall 368. Whenthe housing 308 is assembled, the notch 432 aligns with a correspondingnotch 504 that is defined by the rear portion 348 to define a recess 436that receives a reset button 440. The recess 436 is slightly larger thanthe reset button 440 to allow the button 440 to move or slide within therecess 436.

As shown in FIG. 10 a, the front and rear portions 344, 348 each definea respective channel 444, 508 adjacent the notches 432, 504 that areconfigured to receive a portion of the reset button 440. When thehousing 308 is assembled, the channels 444, 508 align with one anotherand cooperate to at least partially guide the movement of the resetbutton 440 relative to the housing 308 The reset button 440 is slideablealong the channels 444, 508, although in alternate constructions thebutton 440 may pivot, rotate, or the like.

In the present invention, the channels 444, 508 are curvilinear inshape, generally defining a constant radius of curvature over theirlength; however, in alternate constructions, the channels 444, 508 maybe linear or have varying radiuses of curvature. In still otherconstructions, the channels 444, 508 may include ridges or grooves toprovide audible and/or tactile feedback as the reset button 440 movesrelative to the housing 308. In still other constructions, ridges and/orgrooves may be used to lock the reset button 440 into variouspredetermined positions.

Illustrated in FIGS. 10 a-12, the rear portion 348 of the housing 308includes a bottom wall 452 and a rear wall 456 extending upwardly fromthe bottom wall 452. As described above, the periphery 380 of the rearportion 348 substantially corresponds to the periphery 376 of the frontportion 344 to produce the overall housing shape. Best illustrated inFIG. 10 a, the rear portion 348 includes an alignment channel 460extending along at least a portion of the periphery 380 to receive thealignment ridge 384 of the front portion 344. In the illustratedconstruction, at least a portion of rear wall 456 is substantiallyplanar, to allow the housing 308 to lay flat on a support surface in ahorizontal orientation.

The bottom wall 452 of the rear portion 348 is substantiallysemi-elliptical in shape, having a curvilinear edge that at leastpartially defines the contour of the rear wall 456. The bottom wall 452is substantially planar, being configured to rest upon a support surface(e.g., a table top) and maintain the floss dispenser 300 in asubstantially vertical orientation. In some constructions, the bottomwall 452 may include feet or be coated in a high friction material(e.g., rubber) to help stabilize the floss dispenser 300 on a supportsurface.

As shown in FIGS. 9, 11, and 12, the rear portion 348 includes acylindrical shaft 468 extending substantially perpendicularly to therear wall 456 and defining an axis 472. When the floss dispenser 300 isassembled, the shaft 468 supports the supply spool 312 for rotationabout the axis 472. The shaft 468 may be coated with a low frictionmaterial or include bearings (not shown) to reduce rotational frictionbetween the spool 312 and the shaft 468.

The rear portion 348 also includes a plurality of circumferentiallyspaced apart ribs 484 extending radially outwardly from the shaft 468and axially away from the rear wall 456. The ribs 484 position thesupply spool 312 a distance from the rear wall 456 to provide clearancefor the locking mechanism 316 as discussed further below.

As best shown in FIGS. 9, 10 a, and 11, the rear portion 348 of thehousing 308 also defines a substantially annular and recessed track 488defined by the rear wall 456 and substantially concentric with the axis472. The track 488 includes a locking projection 492 extending radiallyinwardly from the outer diameter of the track 488 and substantiallyradially aligned with the notch 504 defining the recess 436 thatreceives the reset button 440 (see FIG. 8 a). In the illustratedconstruction, the projection 492 is substantially triangular in shape,however alternate shapes may be used. The projection 492 is accompaniedby a corresponding side-cut or bypass recess 496 extending radiallyinwardly from the inner diameter of the track 488 substantially oppositethe projection 492. In the illustrated construction, the side-cut 496 isslightly radially off-set from the projection 492 in a counter-clockwisedirection as viewed in FIG. 10 a.

The rear portion 348 also includes a guide pin 500 extendingsubstantially perpendicularly from the rear wall 456 and substantiallyradially opposed to locking projection 492 with respect to the axis 472.When the dispenser 300 is assembled, the guide pin 500 acts as a guidefor movement of the carriage 588 within the housing 308.

Illustrated in FIGS. 9-11, and 32-33, the cap portion 352 of the housing308 is substantially dome-like in shape. The cap portion 352 ispivotably coupled to the housing 308 (e.g., by a living hinge) andmoveable between an open position, in which the top wall 368 isaccessible by the user (see FIG. 32), and a closed position, in whichthe top wall 368 is covered (see FIG. 33). The cap portion 352 protectsthe floss 10 positioned outside the storage volume 340 during storage ornon-use.

The cap portion 352 also includes a locking groove 516 formed in theinner surface of the cap 352. The locking groove 516 fits over a lockingridge 528 formed on the window panel 356 (see FIG. 14 a) to lock ormaintain the cap portion 352 in the closed position. In alternateconstructions, the cap portion 352 may be maintained in the closedposition by any one of a locking tab, reusable adhesive, snap, or thelike.

Illustrated in FIGS. 14 a-16, the window panel 356 of the housing 308 isgenerally oval-shaped and formed from a transparent material. The windowpanel 356 includes a lip 520 that extends about ¾ of the way around thepanel's periphery to retain the window panel 356 within the windowrecess 424. The window panel 356 also includes an axially extendingalignment boss 524 that extends into the storage volume 340 of thehousing 308 and that is at least partially received within the distalend 476 of the shaft 468 when the floss dispenser 300 is assembled. Thewindow panel 356 also includes a ledge 452 (see FIGS. 14 b-14 d)positioned proximate the periphery of the panel 356 and axiallyextending into the storage volume 340 to guide the floss 304 onto theroller 540 as the floss 304 is being removed from the spool 312. In theillustrated construction, the outer surface of the window panel 356corresponds to the curvature of the surrounding front wall 372, givingthe assembled housing 308 an aesthetically appealing appearance.

With reference also to FIGS. 30 and 31, the housing 308 includes a firstalignment member in the form of a spindle 532, and a second alignmentmember in the form of a guide wall 536. In the illustrated construction,the spindle 532 rotatably supports a roller 540 (see FIGS. 17 a-18) at alocation adjacent the periphery 380 within the storage volume 340. Theguide wall 536 is curved and extends inwardly into the storage volume340 from the opening 412 when the front and rear portions 344, 348 arebrought together. The roller 540 and guide wall 536 are positioned todirect the floss 10 between the supply spool 312 and the opening 412.More specifically, the roller 540 and guide wall 536 are spaced from oneanother and work in tandem with the carriage 588 to adjust the lockingmechanism 316 between the locked and unlocked configurations, asdiscussed further below.

In the illustrated construction, the roller 540 is self-centering,having a profile that tapers from enlarged ends 533 to a reduced centerportion 535 (see FIG. 18).

With reference to FIGS. 19 a-21, the supply spool 312 includes acylindrical core 544 defining a central recess or bore 548, a firstflange 552 extending radially from a first end of the cylindrical core544, and a second flange 556 extend radially from a second end of thecylindrical core 544. In some constructions, the diameter of the supplyspool 312 may be greater than a typical dental floss spool. In this way,the curvature of the relatively stiffer portions of the floss 10 removedfrom the spool 312 is reduced. In the illustrated construction, thesupply spool 312 is formed from a first and second portion 560, 564,each coupled to one another by a plurality of locking tabs 568. In otherconstructions, the supply spool 312 may be formed as a single piece. Thecentral bore 548 of the supply spool 312 is sized to receive at least aportion of the shaft 468, thereby allowing the supply spool 312 torotate about the axis 472 with respect to the housing 308.

The supply spool 312 also includes a plurality of teeth 572, eachextending axially from the bottom surface 576 of the second flange 556(see FIGS. 19 a and 19 b). The teeth 572 are spaced evenly over thecircumference of a first reference circle 580 that is concentric withthe cylindrical core 544 and define a plurality of gaps 584therebetween.

With reference to FIGS. 27 and 28, the locking mechanism 316 includes acarriage 588, a disk 592 rotatable with respect to the carriage 588, anda reset button 440. As described above, the locking mechanism 316controls the amount of floss 10 that can be removed from the housing 308at any one time by changing between an unlocked configuration, in whichfloss 10 can be freely removed from the housing 308, and a lockedconfiguration, in which a limited amount or no floss 10 can be removedfrom the housing 308. The locking mechanism 316 controls the removal offloss 10 from the floss supply 304 by selectively allowing andpreventing rotation of the supply spool 312 with respect to the housing308. When the locking mechanism 316 is in the unlocked configuration,the supply spool 312 is free to rotate with respect to the housing 308.When the locking mechanism 316 is in the locked configuration, rotationof the supply spool 312 is limited or restricted. In alternativeembodiments, the locking mechanism 316 may control the removal of floss10 from the floss supply 304 by, for example, directly engaging thefloss 10, automatically severing the floss 10 from the floss supply 304when a desired floss fragment 320 has been removed, or the like.

Referring also to FIGS. 22 a-24, the carriage 588 of the lockingmechanism 316 includes a generally circular main body 596, a first arm600 extending radially from one end of the main body 596, and a secondarm 608 extending radially from an opposite end of the body 596 oppositethe first arm 600. The main body 596 includes an annular wall 616defining an inner and outer diameter, and a generally cylindrical outerwall 620 extending upwardly from the outer diameter of the annular wall616. The annular wall 616 and the outer wall 620 are sized andconfigured to receive the disk 592 in a manner that allows the disk 592to rotate freely with within the carriage 588 while maintainingsubstantially concentric alignment of the disk 592 with the main body596.

The first arm 600 of the carriage 588 defines an elongated slot 604 thatreceives the guide pin 500 (see FIGS. 27 and 28). The second arm 608defines a convex floss engaging surface 624 that cooperates with thefirst and second alignment members 532, 536 to define a serpentine paththrough which the floss 10 travels (see FIGS. 30 and 31) when pulledfrom the supply spool 312 and drawn through the opening 412. In theillustrated construction, the floss engaging surface 624 is curved,producing a smooth transition between the first and second alignmentmembers 532, 536. However, in alternate constructions, the flossengaging surface 624 may include a pulley or define a groove. The secondarm 608 also includes a radially-extending locking tab 628.

The carriage 588 is moveable in a generally linear direction between afirst position in which the main body 596 is eccentric relative to theaxis 472 (see FIG. 27), and a second position in which the main body 596is concentric with the axis 472 (see FIG. 28). Movement of the carriage588 is guided and limited at least partially by movement of the guidepin 500 within the slot 604 in the first arm 600. A biasing member 612is secured within the housing 308 and, in the illustrated construction,engages the second arm 608 to bias the carriage 588 toward the firstposition.

As shown in FIGS. 25 a-26, the disk 592 is substantially annular andincludes a cylindrical core 636 defining a first outer diameter, and aflange 640 extending radially outwardly from a first end of the core 636to define a second outer diameter greater than the first outer diameter.The disk 592 also includes a pair of protrusions 644 extending axiallyfrom the flange 640. The protrusions 644 are substantially diametricallyopposed to one another and are spaced by a distance that corresponds tothe diameter of the reference circle 580 associated with the teeth 572of the supply spool 312. The disk 592 also includes a stopping lug 652extending axially from the cylindrical core 636 of the disk 592. The lug652 includes a ramped edge 656 along one side. As mentioned above, thedisk 592 is received by the main body 596 and is moveable therewithbetween the first and second positions.

With reference to FIGS. 29 a-29 e, the reset button 440 includes a mainbody 660, a pair of ridges 664, a biasing member 668, and a releaseaperture 438. The ridges 664 extend outwardly from the body 660 and areslidingly received within the channels 444, 508 of the front and rearhousing portions 344, 348, respectively. The biasing member 668 includesa spring-like arm extending from the body 660, the distal end of whichis received by the anchor recess 512 of the housing 308. In alternateconstructions, a spring, rubber band, or other form of biasing membermay be utilized in place of the biasing member 668. The release aperture438 is generally rectangular and is positioned between the main body660, the ridges 664, and the biasing member 668.

When the dispenser is assembled, the reset button 440 is moveablebetween an upward, neutral position and a lowered, resetting position.For this purpose, a portion of the body 660 extends through the recess436 so the user can manual actuate the reset button 440, e.g., move itgenerally downwardly to the resetting position, from outside the housing308. The reset button 440 also is located and configured such that, whenthe cap portion 352 of the housing 308 is closed, the cap portion 352engages the reset button 440 and similarly moves it generally downwardlyto the resetting position. The outer portion of the body 660 may includegrooves, or be coated in a high friction material (e.g., rubber) to aidthe user in manually actuating the button 440.

As discussed further below, when the reset button 440 is moved from theneutral position to the resetting position, it changes the flossdispenser 300 from the locked configuration, in which the floss 10 maynot be removed from the dispenser 300, to the unlocked configuration, inwhich floss 10 may be removed from the dispenser 300.

To assemble the floss dispenser 300, the window panel 356 is positionedwithin the window recess 424 of the front wall 372. The cutting member416 is then coupled to the top wall 368. The carriage 588 is positionedwithin the housing 308 by aligning the elongated slot 604 with the guidepin 500 of the rear wall 456, and positioning the second arm 608 betweenthe first and second alignment members 532, 536. At this time, thebiasing member 612 also may be coupled between the carriage 588 and thehousing 308. The carriage 588 is then lowered into the storage volume340 until it engages the rear wall 456. The biasing member 612 willthereafter bias the carriage toward the first position in which the mainbody 596 is eccentric relative to the axis 472 (see FIG. 27)

The disk 592 is then positioned within the body 596 of the carriage 588.Because the main body 596 is in the first, eccentric position, the lug652 is positioned within the bypass 496 that extends radially inwardlyfrom the annular track 488 (see FIG. 10 a). The reset button 440 maythen be installed by positioning the ridge 664 within the channel 508 ofthe rear portion 348, while simultaneously positioning the distal end ofthe biasing member 668 in the anchor recess 512. It should beappreciated that the reset button 440 may be installed before thecarriage 588 and/or the disk 592, if desired. In some constructions, abiasing member in the form of a coil spring 672 is positioned about theshaft 468 and engages the ribs 484.

The supply spool 312 is then mounted on the shaft 468 and is thusconcentrically fixed thereto. The spring 672 is therefore positionedbetween the spool 312 and the ribs 484. Upon assembly, the spring 672 iscompressed between the spool 312 and the ribs 484 causing the spring 672to bias the spool 312 axially upwardly against the window panel 356. Theresulting contact between the window panel 356 and the spool 312provides a modest amount of friction that subtly restricts or limitsunwanted rotation of the spool 312 even though the spool 312 isotherwise allowed to rotate. For example, friction between the spool 312and the window panel 356 can prevent the rotational momentum of thespool 312 from continuing to rotate the spool 312 when a user stopspulling on the floss 10.

When the carriage 588 and disk 592 are in the first, eccentric position,the protrusions 644 on the flange 640 of the disk 592 are radiallyoffset with respect to the gaps 584 between the teeth 572 of the supplyspool 312. As such, the supply spool 312 is substantially free to rotateabout the shaft 468 while the disk 592 remains substantially stationarywith the lug 652 positioned within the bypass 496 of the annular track488.

Because the supply spool 312 is substantially freely rotatable, thefloss 10 may be unwound from the spool 312 and positioned within theserpentine path defined between the first and second alignment members532, 536 and the floss engaging surface 624. More specifically, thefloss is extended over the first alignment member 532 (including theroller 540, if present), under the floss engaging surface 624, and alongthe second alignment member 536. The floss is then positioned in theopening 412 defined by the top wall 368 (see FIGS. 30 and 31). Uponinitial assembly, it is preferred that the serpentine path between thefirst and second alignment members 532, 536 is occupied by the lessstiff textured segment 14 b of the floss 10.

To close the housing 308, the front portion 344 is pivoted about thehinge member 360 and mated to the rear portion 348, including alignmentof the alignment pins/recesses 388 a, 388 b with one another, andalignment of the remaining ridge 664 of the reset button 440 with thechannel 444 of the front portion 344. Similarly, the alignment boss 524of the window panel 356 is positioned within the distal end 476 of theshaft 468.

So assembled, the end portion 420 of the floss 10 can be secured withinthe cutting member 416 and the cap portion 352 may be closed. With thecarriage 588 in the first, eccentric position (see FIG. 27), the spool312 is free to rotate to dispense floss 304 through the opening 412.) Toremove a floss fragment 320 from the floss dispenser 300, the userpivots the cap portion 352 into the open position, thereby exposing thetop wall 368 of the housing 308 and the end portion 420 of the floss.The user grasps and pulls the end portion 420, thereby rotating thespool to unwind the floss 10 from the floss supply 304 while withdrawingthe floss 10 from the housing 308. As the floss is unwound from thespool 312 and exits the housing 308, it travels through the serpentinepath defined by the first alignment member 532, the floss engagingsurface 624, and the second alignment member 536.

Initially, the less-stiff textured segment 14 b of the multi-texturefloss 10 passes through the serpentine path and is removed from thestorage volume 340. As the textured segment 14 b is drawn through theserpentine path, the biasing member 612 applies a sufficient biasingforce to maintain the carriage 588 in the first, eccentric position(FIG. 27). Once the textured segment 14 b has passed through theserpentine path, the adjacent stiffer smooth segment 14 a of themulti-texture floss 10 enter the serpentine path. The increasedstiffness of the smooth segment 14 a being drawn through the serpentineapplies increased force against the floss engaging surface 624. Thisincreased force is sufficient to overcome the biasing force applied bythe biasing member 612 and shifts the carriage 588 from the firstposition (eccentric relative to the axis 472, FIG. 27) to the secondposition (concentric relative to the axis 472, FIG. 28). In this regard,the change in the stiffness of the floss being drawn through theserpentine path operates to shift the carriage 588 from the firstposition to the second position.

When the carriage 588 moves to the second position, the end of thelocking tab 628 passes over and latches onto the partition 632, therebylocking the carriage 588 in the second position. The end of the lockingtab 628 also extends at least partially into the release aperture 438 ofthe reset button 440.

With the carriage 588 and the disk 592 shifted to and held in the secondposition, the protrusions 644 of the disk 592 are moved into concentricalignment with the teeth 572 of the supply spool 312. The protrusions644 mesh with the teeth 572 such that the disk 592 and the supply spool312 are coupled together for rotation as a unit. The movement of thedisk 592 from the first position to the second position also causes thelug 652 to move from the side-cut 496 into the annular portion of thetrack 488. Engagement between the ramped edge 656 of the lug 652 and thelocking projection 492 urges the disk 592 in the clockwise direction asviewed in, for example, FIG. 10 a, which further facilitates engagementof the protrusions 644 and the teeth 572. Once the protrusions 644 areengaged with teeth 572 of the supply spool 312, additional floss removalcauses the spool 312 and the disk 592 to rotate such that the lug 652travels along the track 488 in a clockwise direction.

After approximately one full rotation about the track 488, the lug 652contacts the locking projection 492, which restricts further rotation ofthe disk 592 and the supply spool 312 about the axis 472 thus preventingthe user from removing additional floss 10 from the housing 308. Thecircumference of the spool 312 and the length of the smooth segments 14a are selected such that the length of floss dispensed by one rotationof the spool 312 is less than the length of the smooth segments 14 a. Insome embodiments, the length of the smooth segments 14 a and thecircumference of the spool 312 are selected such that when the lug 652engages the locking projection 492 and prevents further rotation of thespool 312, the next textured segment 14 b is positioned within theserpentine path but has not yet been withdrawn through the opening 412in the housing 308. In this way, there remains a portion of the smoothsegment 14 a extending between the opening 412 and the cutting member416.

The user then uses the cutting member 416 in the traditional manner tocut the floss within the smooth segment 14 a of the multi-texture floss10. Cutting the floss in this manner forms the tail 332 of the flossfragment 320 that has just been removed from the housing 308, and leavesthe leader 324 of the subsequent floss fragment 320 secured to thehousing by the cutting member 416.

To remove a subsequent floss fragment 320 from the floss dispenser 300,the user moves the reset button 440 into the resetting position. Whenthe reset button 440 is moved to the resetting position, an edge of therelease aperture 438 contacts the end of the locking tab 628, therebydisengaging the locking tab 628 from the partition 632 and allowing thecarriage 588 to return to the first position under the influence of thebiasing member 612. As the carriage 588 moves toward the second,eccentric position, it carries the disk 592 with it, which moves the lug652 back into the bypass 496. The contour of the bypass 496 advances thedisk 592 in a clockwise direction and moves the lug 652 past the lockingprojection 492.

Also during movement of the carriage 588 toward the second position, theprotrusions 644 of the disk 592 are moved out of alignment with theteeth 572 of the supply spool 312. As a result, the supply spool 312 andthe disk 592 are no longer coupled for rotation together, and the supplyspool 312 is able to rotate freely, thereby allowing a user to withdrawadditional floss to form an additional floss fragment 320.

In some constructions, including the illustrated construction, the resetbutton 440 is configured such that closing the cap portion 352 of thehousing 308 moves the reset button 440 to the resetting position andresets the floss dispenser 300.

FIGS. 34-43 illustrate an alternate embodiment of a floss dispenser 300′for dispensing the multi-texture floss 10. The floss dispenser 300′contains much of the same structure and has many of the same propertiesas the floss dispenser 300 illustrated in FIGS. 8 a-33. Common elementshave been given the same reference numbers with an added prime symbol.The following description focuses primarily upon structure and featuresof the floss dispenser 300′ that differ from those of the flossdispenser 300.

Illustrated in FIGS. 39, 40, and 42, the rear portion 348′ of the flossdispenser 300′ includes an outer annular wall 700′ extendingsubstantially perpendicularly therefrom. The outer annular wall 700′ isgenerally centered on and extends a distance from the rear portion 348′to define a distal edge 704′ proximate the front portion 344′ (see FIG.39). The outer annular wall 700′ also defines a slot 708′ for floss 10to pass therethrough.

The rear portion 348′ also includes an inner annular wall 712′concentric with and positioned radially inward from the outer annularwall 700′ (see FIG. 39). In the illustrated construction, the innerannular wall 712′ includes a plurality of fingers 716′, each extendingsubstantially perpendicular from the rear portion 348′. When thedispenser 300′ is assembled, the inner annular wall 712′ and the outerannular wall 700′ cooperate to define a substantially annular volumesized to at least partially receive a portion of the supply spool 312′therein.

The floss dispenser 300′ also includes a metering element 720′positioned within the storage volume 340′ and located between the slot708′ of the outer annular wall 700′ and the opening 412′. During flossdispensing, the metering element 720′ resists the removal of the floss10 from the housing 308′. More specifically, the level of resistanceprovided by the metering element 720′ varies dependent upon one or moreproperties of the section of floss 10 engaging the metering element720′. The front portion 348′ includes a wall 721′ that, when the housing308′ is closed, is positioned between the slot 708′ and the meteringelement '720 and guides the floss 10 toward the metering element '720.When the floss dispenser 300′ is assembled, the floss 10 is routed awayfrom the spool 312′ by passing it through the slot 708′ of the outerannular wall 700′, through the metering element 720′, and out theopening 412′ so it can be grasped by the user (see FIG. 43).

In the illustrated construction, the level of resistance provided by themetering element 720′ is dependent upon the stiffness of the section offloss 10 that is in engagement with the metering element 720′. Morespecifically, when the section of floss 10 in engagement with themetering element 720′ has a first stiffness, a first resistance isproduce that requires a first pulling force to remove the floss 10 fromthe dispenser 300′. Similarly, when the section of floss 10 inengagement with the metering element 720′ has a second stiffness greaterthan the first stiffness, a second resistance is produced, greater thanthe first resistance, that requires a second pulling force, greater thanthe first pulling force, to remove the floss 10 from the dispenser 300′.In alternate constructions, the resistance provided by the meteringelement 720′ may depend on other floss properties such as diameter,texture, material composition, and the like. In still otherconstructions, the resistance provided by the metering element '720 maybe based on a combination of floss properties.

Illustrated in FIGS. 40 and 43, the metering element 720′ includes aplurality (e.g., two) of substantially cylindrical protrusions 724′spaced a distance from one another and positioned between the slot 708′and the opening 412′. The illustrated protrusions 724′ each include anoptional thin wall 728′ extending radially outwardly therefrom. Whenassembled, the floss 10 extends between the cylindrical protrusions 724′in a substantially serpentine path before exiting through the opening412′ (see FIG. 43). The orientation of the walls 728′ and the distancebetween the cylindrical protrusions 724′ cooperate to resist themovement of the floss 10 along the serpentine path. The distance betweenthe cylindrical protrusions 724′ and the orientation or stiffness of thewalls 728′ can be adjusted to alter the amount of resistance provided.

With reference also to FIGS. 44-48, the supply spool 312′ includes acylindrical core 544′ defining a central recess or bore 548′, a firstflange 552′ extending radially from a first end of the cylindrical core544′, and a second flange 556′ extend radially from a second end of thecylindrical core 544′. In some constructions, the diameter of the supplyspool 312′ may be greater than a typical dental floss spool. In thisway, the curvature of the relatively stiffer portions of the floss 10removed from the spool 312′ is reduced. The central bore 548′ of thesupply spool 312′ is sized to receive at least a portion of the innerannular wall 712′ therein, allowing the supply spool 312′ to freelyrotate in both directions about an axis with respect to the housing308′. The outer diameters of the first flange 552′ and the second flange556′ substantially correspond with the inner diameter of the outerannular wall 700′ to stop floss from uncoiling from the spool 312′ whenthen dispenser 300′ is not in use.

The front portion 344′ of the housing 308′ defines an opening oraperture 726′ that allows a user to manually engage and rotate the spool312′ to rewind floss, for example, when the user has pulled off morefloss than he/she would like to use. Unlike standard floss dispensers,which would require the user to disassemble the housing in order torewind inadvertently removed floss, the housing 308′ is configured topermit the user to rewind the floss without having to disassemble orotherwise manipulate the housing 308′. When floss 10 is uncoiled fromthe spool 312′, the spool 312′ rotates in a first direction 732′ withrespect to the housing 308′ (e.g., in the clockwise direction as viewedin FIG. 43). To rewind the floss onto the spool 312′, the user canmanually rotate the spool 312′ in a second direction 736′, opposite thefirst direction 732′ (e.g., the counter-clockwise direction as viewed inFIG. 43), to coil the floss 10 back onto the spool 312′ (see also FIG.34). In the illustrated construction, the spool 312′ includes aplurality (e.g., four) of ridges 740′ that are radially spaced along thefirst flange 552′ and that are accessible to the user through aperture726′ formed in the front portion 344′ of the housing 308′. In theillustrated construction, the user can rotate the spool 312′ in eitherdirection by engaging the ridges 740′ and manually rotating the spool312′. Dependent upon the direction of rotation, this can cause the floss10 to wind (e.g., by rotating in the second direction 736′) or unwind(e.g., by rotating in the first direction 732′) from the spool 312′.

While the illustrated embodiment includes an aperture 726′ on a frontface of the housing 308′ that affords access to the first flange 552′ ofthe spool 312′, other embodiments may include an aperture on the side ofthe housing 308′ that affords access to the outer diameter of the spool312′, or to some other portion of the spool. Also, different embodimentscan include handles, cranks, projections, and other features that may beformed integral with or separate from the spool 312′ and that permit auser to manually rotate the spool 312′ at least in a direction thatcoils or winds the floss back onto the spool 312′.

To assemble the dispenser 300′, a spool 312′ with a length of floss 10wound thereon is loaded into the housing 308′, making sure the innerannular wall 712′ is received within the bore 548′ of the spool 312′.The floss 10 is then fed through the slot 708′, passed through theserpentine path of the metering element 720′ and fed through the opening412′. The housing 308′ can then be closed.

To operate the device, the user grasps the end of the floss 10 and pullsto begin dispensing the floss 10 from the housing 308′. When theless-stiff segment 14 b of the multi-texture floss 10 is in engagementwith the metering element 720′ (e.g., the segment 14 b is positioned inthe serpentine path) and is being removed from the storage volume 340′,pulling the floss 10 from the housing 308′ requires the user to exert apulling force having a first, relatively lower magnitude to withdraw thefloss 10 from the housing 308′. Once the textured segment 14 b haspassed through the serpentine path, the adjacent stiffer segment 14 a ofthe multi-texture floss 10 engages the metering element 720′ and entersinto the serpentine path. As the stiffer segment 14 a passes through theserpentine path the resistance provided by the metering element 720′increases, thus, pulling the floss 10 from the housing 308′ while thesegment 14 a is engaged with the metering element 720′ requires the userto exert a pulling force having a second, relatively higher magnitude towithdraw the floss 10 from the housing 308′. Stated differently, asfloss is being withdrawn from the housing 308′, the user experiences anincrease in resistance just before the stiffer segment 14 a begins toemerge from the housing 308′. The differences in the resistance providedby the metering element 720′ generally correspond to the differences inbending stiffness of the segments 14 a and 14 b, which is to say thatthe stiff segments 14 a have a higher bending stiffness, and therefore ahigher resistance to movement through serpentine path, than the segments14 b.

By providing the user with an indication that a stiffer segment 14 a isabout to emerge from the housing 308′, the dispenser 300′ aids the userin severing the floss in approximately the middle of the stiff segment14 a. By severing the floss in the middle of the stiff segment 14 a, theuser ends up with a length of floss where at least one end of the flossis relatively stiff and can be used as a “leader” or “threader” forinserting the end of the floss into interdental spaces, or into thespaces between braces, bridges, and other dental work that cannot beaccessed using traditional flossing techniques. As discussed above,coloring can be applied to at least one of the segments 14 a, 14 b tofurther aid a user in severing the floss in the approximate middle ofthe stiff segment 14 a. For example, by coloring the stiff segments 14 agreen and leaving the segments 14 b white, or by coloring the segments acolor other than green, a user can easily identify the stiff segments 14a and sever the floss appropriately.

If a user is diligent about repeatedly severing the floss in theapproximate middle of the stiff segment 14 a, he or she willconsistently be provided with a length of floss where each end isrelatively stiff and can be used as a “leader” or “threader.” Of course,if the user wants to dispense multiple floss fragments without regard towhere the floss is severed, the user can continue to remove floss fromthe dispenser 300′ until the desired length is achieved. When thisoccurs, after the initial increase in resistance (e.g., corresponding tothe stiff segment 14 a engaging the metering element 720′), theresistance will reduce as a second less-stiff segment 14 b, adjacent thefirst stiff segment 14 a, enters the serpentine path and engages themetering element 720′. As such, the user will experience one resistance“bump” for each stiff segment 14 a that is dispensed.

FIGS. 49-51 illustrate an alternate embodiment of a floss dispenser 300″for dispensing the multi-texture floss 10. The floss dispenser 300″contains much of the same structure and has many of the same features asthe floss dispenser 300′ illustrated in FIGS. 34-43. Common elementshave been given the same reference numbers with a double prime symbol.The following description focuses primarily upon structure and featuresof the dispenser 300″ that are different from the dispenser 300′.

As shown in FIGS. 50 and 51, the metering element 720″ of the dispenser300″ includes a protrusion 744″ extending generally forwardly from therear portion 348″ and forming a groove 748″ therein. Other embodimentsmay include a pair of resilient fingers extending forwardly from therear portion 348″ and defining the groove 748″ therebetween. In eitherembodiment, the groove 748″ is oriented substantially along an imaginaryline extending between the slot 708″ and the opening 412″.

The front portion 344″ of the housing includes a substantiallyrectangular and hollow box structure 750″ that extends generallyrearwardly from the front portion 344″ and that is positioned andoriented to fit over the protrusion 744″ when the front portion 344″ isclosed with respect to the rear portion 348″. The box structure 750″functions as a clamping structure for controlling the width of thegroove 748″. When the dispenser 300″ is assembled, the floss 10 passesthrough the slot 708″, through the groove 748″, and out the opening 412″where it can be grasped by the user.

The width of the groove 748″ and its relationship with the dimensions ofthe floss 10 determine how much pulling force is required to withdrawthe floss 10 from the housing 308″. For example, making the groove 748″thinner will increase the resistance on the floss 10, and making thegroove 748″ thicker will reduce the resistance on the floss 10, assumingproperties of the floss 10 stay constant. The width of the groove 748″and the pressure it applies to the floss 10 can be varied by changingthe configuration of the protrusion 744″ or by changing theconfiguration of the box structure 750″. When the housing 308″ is closedthe box structure 750″ receives the ends of the protrusion 744″ andpinches them together. Thus, by narrowing the box structure 750″, thegroove 748″ will also be narrowed once the housing 308″ is closed. Insome embodiments, a small insert (not shown) can be inserted into thebox structure 750″ to narrow the width of the box structure 750″ andpinch the ends of the protrusion 744″ closer together. In this way, thesame housing, either with or without an insert, can be used to dispensespools carrying flosses of different thicknesses.

Like the dispenser 300′, when the less stiff floss segment 14 b ispositioned in the groove 748″, pulling the floss from the dispenser 300″requires the user to exert a pulling force having a first, relativelylower magnitude, and when the stiff floss segment 14 a is positioned inthe groove 748″, the resistance on the floss increases and the user mustapply a pulling force having a second, relatively higher magnitude. Inthe dispenser 300′, the differences in the resistance provided by themetering element 720″ generally correspond to the differences inresistance to compression of the segments 14 a and 14 b. Generallyspeaking, the treated stiff segments 14 a are less deformable than thesegments 14 b, and when being drawn through the groove 748″, the stiffsegments 14 a maintain a larger cross section than the segments 14 b,which include fibers that are able to deform and flatten as they passthrough the groove 748″.

The invention claimed is:
 1. A dental floss dispensing unit comprising:a housing; a supply spool coupled to the housing and having a length offloss wound thereabout, the length of floss including a free endextending from the housing; and a metering element coupled to thehousing and operatively engaging a portion of the length of floss,wherein the metering element provides resistance against removal of thelength of floss from the housing, a magnitude of the resistance againstremoval of the length of floss from the housing is dependent upon atleast one property of the portion of the length of floss engaging themetering element, the supply spool rotates with respect to the housingduring removal of the length of floss from the housing, and themagnitude of the resistance against removal of the length of floss fromthe housing is independent from rotation of the supply spool.
 2. Thedental floss dispensing unit of claim 1, wherein the at least oneproperty of the portion of the length of floss engaging the meteringelement includes stiffness.
 3. The dental floss dispensing unit of claim1, wherein the metering element defines a serpentine path through whichthe length of floss extends.
 4. The dental floss dispensing unit ofclaim 1, wherein the metering element defines groove, and wherein thelength of floss extends through the groove.
 5. The dental flossdispensing unit of claim 1, wherein the length of floss includesalternating first segments and second segments, the first segmentshaving a first property and the second segments having a second propertydifferent from the first property.
 6. The dental floss dispensing unitof claim 5, wherein the first property and the second property areassociated with one of a stiffness, a thickness, and a texture of therespective first and second segments.
 7. The dental floss dispensingunit of claim 6, wherein the first segments have a first color andwherein the second segments have a second color different from the firstcolor.
 8. The dental floss dispensing unit of claim 5, wherein the firstsegments are stiffer than the second segments, and wherein the meteringelement provides a greater magnitude of resistance against removal ofthe length of floss from the housing when the first segments are engagedwith the metering element than when the second segments are engaged withthe metering element.
 9. The dental floss dispensing unit of claim 1,wherein the housing defines an aperture, and wherein the apertureprovides access to the supply spool for manual rotation of the supplyspool.
 10. The dental floss dispensing unit of claim 9, wherein pullingthe free end of the length of floss uncoils the length of floss from thesupply spool, and wherein manually rotating the supply spool coils thelength of floss onto the supply spool.
 11. The dental floss dispensingunit of claim 1, further comprising a floss cutter coupled to thehousing.
 12. A dental floss dispensing unit comprising: a housing; asupply spool coupled to the housing and having a length of floss woundthereabout, the length of floss having a plurality of alternating anddistinct first and second floss segments; and a metering elementengaging the length of floss and providing resistance to removal of thelength of floss from the housing, wherein a magnitude of the resistancechanges as each floss segment moves into engagement with the meteringelement, the metering element defines a serpentine path through whichthe length of floss extends, the first floss segments are stiffer thanthe second floss segments, and the magnitude of the resistance increaseswhen the stiffer first floss segments are pulled through the serpentinepath.
 13. The dental floss dispensing unit of claim 12, wherein theresistance increases when a first floss segment moves into engagementwith the metering element.
 14. The dental floss dispensing unit of claim12, wherein the first segments are stiffer than the second segments. 15.The dental floss dispensing unit of claim 12, wherein the supply spoolrotates with respect to the housing as the length of floss is removedfrom the housing, and wherein the change in the magnitude of theresistance is independent from the rotation of the supply spool.
 16. Thedental floss dispensing unit of claim 12, wherein the metering elementis biased into engagement with the length of floss and includes a groovethrough which the length of floss extends.
 17. The dental flossdispensing unit of claim 16, wherein the first floss segments are moreresistant to compression than the second floss segments, and wherein themagnitude of the resistance increases when the first floss segments arepulled through the groove.
 18. A dental floss dispensing unitcomprising: a housing defining an interior volume and an openingcommunicating with the volume; and a length of dental floss contained bythe volume and having a free end extending through the opening, thelength of dental floss including a plurality of alternating first andsecond segments, the first segments having a first physical property andthe second segments having a second physical property different from thefirst physical property, wherein the housing provides a tactilelydetectable indexing as alternating first and second segments arewithdrawn from the housing, and the housing includes a reduced aperturethrough which the length of dental floss extends and that provides thetactilely detectable indexing.
 19. The dental floss dispensing unit ofclaim 18, further comprising a spool rotatably mounted in the housingand about which the length of dental floss is wound.
 20. A dental flossdispensing unit comprising: a housing defining a volume; a supply spoolcarried by the housing and positioned within the volume; and a length offloss wound about the supply spool and having a free end extending fromthe housing, wherein the free end can be pulled to unwind floss from thesupply spool, without manipulating the housing the supply spool ismanually rotatable to rewind floss onto the supply spool, the supplyspool rotates with respect to the housing during removal of the lengthof floss from the housing, and the magnitude of the resistance againstremoval of the length of floss from the housing is independent fromrotation of the supply spool.
 21. The dental floss dispensing unit ofclaim 20, wherein the housing defines an aperture, and wherein thesupply spool is accessible by the user through the aperture.
 22. Thedental floss dispensing unit of claim 20, wherein the aperture exposes afront flange of the supply spool.
 23. The dental floss dispensing unitof claim 20, wherein the supply spool includes a plurality of fingerridges.